NEW POLY(AMIDE-IMIDE)S SYNTHESES .7. PREPARATION AND PROPERTIES OF POLY(AMIDE-IMIDE)S DERIVED FROM 1,5-BIS(4-AMINOPHENOXY)NAPHTHALENE, TRIMELLITIC ANHYDRIDE, AND VARIOUS AROMATIC DIAMINES

New bis (phenoxy) naphthalene-containing poly (amide-imide) s having an inherent viscosity in the range of 0.62-1.09 dL/g were prepared by the direct polycondensation of 1,5-bis(4-trimellitimidophenoxy)naphthalene (I) and various aromatic diamines using triphenyl phosphite and pyridine as condensing agents in N-methyl-2-pyrrolidone (NMP) in the presence of calcium chloride. The diimide-diacid (I) was prepared by the condensation of 1,5-bis(4-aminophenoxy) naphthalene and trimellitic anhydride. Most of the polymers were soluble in aprotic solvents such as NMP and N,N-dimethylacetamide (DMAc), and afforded transparent, flexible and tough films upon casting from DMAc solutions. Measurements of wide-angle X-ray diffraction revealed that those polymers containing p-phenylene or oxyphenylene groups were characterized as crystalline polymers. Tensile strength and initial moduli of the polymer films ranged from 61-86 MPa and 1.83-2.21 GPa, respectively. Glass transition temperatures of the polymers were in the range of 231-340-degrees-C. The melting points of the crystalline polymers ranged from 375-430-degrees-C. The 10% weight loss temperatures were above 512-degrees-C in nitrogen and 481-degrees-C in air. (C) 1993 John Wiley & Sons, Inc.